John Key and John Banks have wound up their "cup of tea" meeting at a central Auckland cafe, with the Prime Minister telling Epsom voters he would "not be unhappy" if they vote tactically and back Banks in the pivotal electorate.

National had "a very good constructive working relationship" with ACT and other parties and could do it again, Key said.

"The outcome of the election is a matter for New Zealand voters. But if we were in a position, post 2011 to be working alongside the ACT Party again, along with the Maori Party and United Future, I wouldn't be at all unhappy about that," Key said.

Key himself is a voter in the Epsom electorate and confirmed today he would vote National on both the party and electorate vote. However, he said he had "a pretty simple message for Auckland voters".

"In 2005 and 2008 they gave their party vote to National and their electorate vote to ACT, and if they were to do that in 2011, I wouldn't be at all unhappy about that.

"I'm not telling anyone to vote in a particular way because I don't think it's right to tell anyone how to vote but what I am saying is that we've had a very good working relationships with ACT and we wouldn't be at all unhappy if they were back in Parliament. If they decide to tactically vote and split their vote, I wouldn't be unhappy about that."

In 2008, Key ruled out Roger Douglas as a minister in his Government, but today said he could work with Don Brash, the current leader of ACT, as a minister.